Mgv7 floatlands: Various improvements

Floatland base terrain underside was too thin, causing excessive water
leakage through tunnels under lakes, now make it thicker.
Floatland mountain terrain had a rim 1 node thick which made it bare
stone, now make it 2 nodes thick to merge with the floatland base
terrain rim and to have a layer of biome material.
Make mountain terrain more exponentially shaped by altering the
exponent.
Remove unnecessary and potentially ugly MYMAX() applied to
n_base_height.

diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index c4fa024a80cb0ba455e3066a7c8fef387dc72ecb..498a1333ccb382a1ea3e5277df795fb03183b92f 100644 (file)
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -346,8 +346,11 @@ bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, s16 y)
 
 bool MapgenV7::getFloatlandMountainFromMap(int idx_xyz, int idx_xz, s16 y)
 {
-       float density_gradient =
-               -pow(fabs((float)(y - floatland_level) / float_mount_height), 0.8f);
+       // Make rim 2 nodes thick to match floatland base terrain
+       float density_gradient = (y >= floatland_level) ?
+               -pow((float)(y - floatland_level) / float_mount_height, 0.75f) :
+               -pow((float)(floatland_level - 1 - y) / float_mount_height, 0.75f);
+
        float floatn = noise_mountain->result[idx_xyz] + float_mount_density;
 
        return floatn + density_gradient >= 0.0f;
@@ -362,11 +365,10 @@ void MapgenV7::floatBaseExtentFromMap(s16 *float_base_min, s16 *float_base_max,
 
        float n_base = noise_floatland_base->result[idx_xz];
        if (n_base > 0.0f) {
-               float n_base_height =
-                       MYMAX(noise_float_base_height->result[idx_xz], 0.0f);
+               float n_base_height = noise_float_base_height->result[idx_xz];
                float amp = n_base * n_base_height;
                float ridge = n_base_height / 3.0f;
-               base_min = floatland_level - amp / 2.0f;
+               base_min = floatland_level - amp / 1.5f;
 
                if (amp > ridge * 2.0f) {
                        // Lake bed